<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>CSS z-index Property</title>
<style>
<!--

#a,#b,#a-1,#b-1{width:100px;height:100px;color:#FFF;}
#a{padding:10px;background:#F99;}
#b{padding:10px;background:#99F;margin:-50px 0 0 25px;}
#a-1{background:#C00;}
#b-1{background:#00C;}

-->
</style>
</head>
<body>

<div id="a" style="position:relative;z-index:1;">
	<div id="a-1">A-1</div>
</div>

<div id="b" style="position:relative;z-index:0;">
	<div id="b-1">B-1</div>
</div>

</body>
</html>